This invention is directed to marine propulsion devices which generally utilize an internal combustion engine mounted inboard of the boat and often disposed adjacent the transom at the boat stern. A stern drive unit is usually mounted externally of the transom and is suitably connected through the transom to the engine. The engine is normally mounted above the floor of the boat and is provided with an oil pan which depends downwardly therefrom.
Heretofore, when it has been desired to change the engine oil, it has usually been necessary to utilize a pump which sucks the oil out of the oil pan. This requires an investment in additional and often expensive equipment. In addition, it has been found that pumping the oil out through the usual dip stick tube does not remove undesirable contaminents which tend to collect at the bottom of the oil pan.
It is an object of the present invention to eliminate the need for a pumping system to remove the used oil from the oil pan during an oil change, and yet provide for full removal of the oil from the boat. It is a further object to provide an oil removal system which is extremely simple and inexpensive in construction.
In accordance with the various aspects of the invention and in the present embodiment, a fluid flow tube is provided and which extends from the lower portion of the oil pan to a point on the transom below the pan. The upper end portion of the tube is connected through a control valve which communicates with the pan interior. The lower or discharge tube and portion is connected through a fitting extending through the transom. A removable plug is associated with the fitting and, when removed, permits oil to drain out through the transom and into an oil collection receptacle when the control valve is open.